Make KCONFIG_WERROR more verbose.

Index: kconfig/confdata.c
===================================================================
--- kconfig.orig/confdata.c
+++ kconfig/confdata.c
@@ -533,8 +533,10 @@ load:
 	free(line);
 	fclose(in);
 
-	if (conf_warnings && werror)
+	if (conf_warnings && werror) {
+		fprintf(stderr, "\nERROR: %d warnings encountered, and warnings are errors.\n\n", conf_warnings);
 		exit(1);
+	}
 
 	return 0;
 }